Signal receiver for remote control apparatus



NOV. 18, 1941. Q HAIMBAUGH 2,263,298

SIGNAL RECEIVER FOR REMOTE CONTROL APPARATUS Filed July 18, 1940 2Sheets-Sheet 2 I 20/ Z04 /6Z Ham/war! INVENTOR. fflgwo/va 6.Hal/1061107.

Patented Nov. 18, 1941 2,263,298 SIGNAL RECEIVER FOR REMOTE CONTROLAPPARATUS Raymond C. Haimbaugh, North N. Y., assignor to The Rudolphpany, Cincinnati,

Tonawanda, Wurlitzer Com- Ohlo, a corporation Application July 18, 1940,Serial No. 346,130

2 Claims.

This invention relates, to a signal receiver for remote controlapparatus which is particularly adapted to the selective control ofautomatic record changing phonographs. 1

One object of the invention is to provide a remote control in whichselective operation may be accomplished by means of electrical signalstransmitted over power lines supplying the operatingpower for thephonograph and for a remotely positioned transmission apparatus.

Another object of the invention is to provide improved apparatus forreceiving such signals and for operating a phonograph in response tosaid signals.

The invention in its preferred form may be used with a transmitter unitoi' the type 'disclosed in co-pending application of Osborne and Wright,Serial No. 305,920, filed November 24, 1939, although other forms oftransmitters operating upon the same general principle may be used. Thetransmitter is combined with a signal generating unit adapted togenerate electrical signalsof frequencies above the audible range and toapply such signals to the power mains supplying the generating unit andthe phonograph in the form of high frequency modulation of the normalalternating current voltages carried by said power mains.

" hold wiring. The

At the phonograph there is employed a novel form of receiving unitoperating in response to the high frequency signals carried by the powermains and adapted to control the operation of the phonograph inaccordance with such signals.

In the present application the invention has been shown in a form bestadapted to control an automatic record-changing phonograph of the typedisclosed in Wilcox Patent No. 2,002,236, issued May 21, 1935. However,adaptations to the control of other types of apparatus will be apparent.

Other objects and features of the invention will be understood from theaccompanying drawings and the following specification and claims:

Fig. 1 is an elevational view with parts shown in section of mechanicalportions ofva receiver constructed in accordance with a preferred formof the invention. Fig. 2 is a sectional view taken on the line 2-2 ofFig. 1. Fig. 3 is a diagram of electrical connections illustratingelectrical elements used with the apparatus of Figs. 1 and 2, certainparts of said apparatus being-shown diagrammatically therein. Fig; 4 isa diagrammatical drawing illustrating the connection of the transmitterand a phonograph to the power line.

Referring first to Fig. 4, there is shown therein I54 and is normallyurged in a pair of power mains 20 supplying power 22. The mains 20 maybe taken to represent the usual distributory lines from the sub-stationof the public utility, carrying alternating current voltages greaterthanthat allowable for housepower lines 22 are the usual conductorssupplying current for operation of lights and other appliances in thebuilding in which the phonograph is to be used and preferably carryalternating current of 110 volts. cycles. A number of outlet sockets 23are supplied from the power lines 22 and may be used for lightingfixtures 24 or other electrical appliances. In any one of said socketsthere may be inserted a Dlug25 connected by a cable 25 to a transmitterunit 21. In another of said sockets may be inserted a plug 28 connectedto a phonograph cabinet 29 and supp y ng current for operation of saidphonograph and for operation of the signal receiving mechanism which maybe housed in the cabinet of'said phonograph.

The transmitter 21 forms no part of the present invention and'need notbe described in detail. It issuiflcient to say that it is adapted tomodulate the normal voltage of the power lines Any suitable apparatusfor generating such signals and impressing the same on the may beemployed for the purpose.

The mechanical parts of the receiving apparatus are shown particularlyin Figs. 1 and 2. The frame of the receiver consists of a pair of platesI53 and I54 secured together by spacer bolts I 55 and mounted in anyconvenient position adjacent the phonograph preferably within thecabinet of the phonograph itself. A shaft I55 is journaled in the platesI53 and the clockwise direction (Fig.2) by a torsion spring I51. Saidshaft carries a ratchet I58 and a scanning finger I59. The tip of saidscanning finger is adapted to engage electrical contact buttons I60mounted on a dial I6! formed of insulating material and supported in anysuitable manner on the plate I53. An electromagnet I62 is mounted on abracket I63 secured to the plate I54 and when energized serves to liftan armature I54 pivotally mounted at I65. Said armature has securedthereto by means of a vertical pivot pin I56 an Dower lines arm I61. Theresulting stricted upward movement released from the arm I61 projectingforwardly'through a suitable opening in the plate the lower cornerof-said opening. Each actuation of the magnet I62 lifts the armature I64and I engagement of said arm with the /teeth of the ratchet wheel I58moves said wheel in the counterclockwise direction of Fig, 2 a distancecorresponding to one tooth.

A pawl- I69 pivotally mounted on the plate I53 at I18 is urged by atension spring I1I'toward engagement with the teeth of the ratchet wheelI58. 'An arm I12 pivotally mounted at I13.

extends, through a suitable opening in plate I53 to engage the tailofthe pawl I69. Said arm is urged downwardly by a tension spring I14. Arod I15 ispivotally connected at its upper end to the arm I6I and restsat its lower end on the armature I64. Areduced extension I16 of saidmally rests on the pawl 'I69andis held in that position bythe springI14. vSaid pawl is thus and the spring I51 holds said ratchet wheel inan idle position in which a stop pin I19 carried by said wheel engages astop member I88 carried by the plate I53. The electromagnet I62 isoperated in. response the remote stations as will be describedhereinafter. The first of a series of such signals causes 1 said magnetto move the ratchet wheel one space been found satisfactory for teeth ofthe ratchet wheel I58 to indexing signals from I53 and-normally retained.by a diagonally arranged tension spring I68 in I the same in properrelation thereto. A dashpot I11 in the counterclockwise direction. Atthe same time the rod I15 lifts the arm I12 from the tail of' the pawlI69 and permits the pawl to engage the teeth of the ratchet to retainthe same in its new'position. Succeeding-indexing signals arrive atpredetermined time intervals. The action of the dashpot I11 is so timedwith relation to the timing of the signals that the arm I12 cannotreengage the pawl I69 in the interval between two successive signals. Aslong as a series of indexing signals continues, the ratchet I58 is movedone 'step by each signal and the pawl I69 prevents return movement. Atthe conclusion of a series, the spring I14 returns the arm I12 slowly toits original position, releases the pawl I69 and permits the ratchetwheel I58 to return to its original position under the influence ofspring I51. During the movement of the ratchet wheel I58 the scanningmember I59 restson a different one of the contact buttons I68 at eachposition. Thus the scanning member I59 is moved in synchronism with thesignals .in the indexing series and engages a particular contact buttonduring and immediately after each indexing signal of the series. I

Electrical circuitsassociated with the receiver just described areshownin Fig. 3. The plug 28 shown in said figure and in Fig. 4, wheninserted in one of the sockets 23, provides a direct connection betweenthe power lines 22 of Fig. 4 and a pair of power lines I98 and I9I ofFig. 4. The last mentioned power lines therefore receive the usualcommercial alternating current modulated by the high frequency signalsgenerated at the transmitter. Power for operating'the controlled machinemay be taken from the power lines I98 and I9I as shown in the drawingsby connection of these lines to the rectangle marked "Phonographmechanism.

A pair of input transformers I92 and I99 have their primary windingsconnected across the power lines I98 and I9I through condensers I94 andI95 respectively. The secondary windings of the transformers I92 and I93are connected in the grid circuit of an amplifier tube I98 which may bethe usualmentode tube connected in the conventional manner shown in thedrawings. The circuits of the transformers I92 and I93 are tuned totransmit to the amplifier tube only high frequency energy having thefrequencies of the indexing and selection signals respectively. Directcurrent for operationof the amplifier tube I96 is supplied by arectifier I91 which establishes the necessary direct current potentialbetween a conductor I98 and the power line I98 which serves as the highvoltage direct current distributory as well as an alternating currentpower line.

The output circuit of the tube I96 is connected to the primary windingsof a pair of transformers I99 and 288. The secondary windings of I saidtransformers are provided with bridging condensers 28I and 282 properlychosen to provide tuned circuits sensitive respectively to \thefrequencies of the indexing and selection .signals. One terminal ofeachof said secondary windings is connected to the low voltage directcurrent conductor I98 through a resistance 283. The opposite terminal ofthe secondary winding of transformer I99. is connected to the controlgrid of a gas filled triode discharge tube 284 and the'secondary windingof transformer 288 is similarly connected to a similar tube 285. Theanode of the tube 284is connected through a relay coil 286, anorm'allyopen switch 281 and a radio fre quency choke coil 288 to the power lineI9I. The anode of the tube 285 is similarly connected through a relaycoil 289. The cathodes of the tubes 284 and 285 are connected to thepower line I98. Thus when the switch 281 is closed, alternating voltageis established between the anodes and cathodes of said tubes. In theidle condition of the apparatus, however, the control grids of saidtubes are biased to cut off by their connection through the secondarywindings of the transformers I99 and 288 to the low voltage directcurrent line I98. Thus, inthe absence of a high frequency signal, nocurrent flows through the tubes 284 and 285. The presence of a signalvoltage of the predetermined high frequency in the transformers I99 and288 causes the potential of the control grids of said tubes to be raisedsuiiiciently on alternate half cycles to pass current through said tubesto operate the relay coils 286 and 289. a

To prevent establishing the alternating voltage across the elementsofsaid tubes before the control grids can be biased to cutoff; a directcurrent v relay coil 2 I8 is connected between the power line I98 andthe lowvoltage direct current line I98 and serves when energized toclose the switch 281. Thus, when current is first established, the

direct current voltage must be built up sufliciently to operate therelay coil 2" and to biasthe grids of tubes 284 and 285 before switch281 may be closed to establish the alternating potential across saidtubes. Ame use of the relay 2I8 .tubes by pulling and frequency of theselection of the scanning arm thus prevents unauthorized operation ofsaid replacing the plug 28.

By means of the wiring just described, the high frequency modulationsreceived on the power lines I90 and I 9| are amplified by the tube I96and are caused to operate the discharge tubes 204 and 205.. Thecharacteristics of the circuit associated with tube 204 are such that itre-, sponds only to the frequency of the indexing signal: Similarly thecharacteristics of the circuits associated with the tube 205 respondonly to the signal. Thus the relay 206 is actuated in response to eachindexing signal and the relay 209 is actuated in response to eachselection signal.

The relay 206 when actuated closes a switch 2 which connects theelectromagnet I62 of the receiver directly across the power lines I90and I9I and thus actuates said magnet to move the scanning member I59.The relay 209 when actuated in response to each selection signal closesa switch 2I2 which-connects the scanning arm I59 to the power line I90.Each of the contact buttons I60 is connected to one of a series ofelectromagnets 2I3, each of which is adapted to control an operation ofthe machine. When op-- crating a phonograph of the type shown in WilcoxPatent No, 2,002,236; the magnets 2I3 correspond to the magnets I15 ofthe Wilcox machine, each of which is adapted to control the selection ofa predetermined record for playing..

Each of said magnets has its opposite terminal connected to the powerline I 9| and thus the closure of switch 2I2 causes the actuation of oneof. said magnets depending upon the position I59. A magnet coil 2 isconnected directly between the switch 2I2 and the power line I9I and isthus actuated each time that one of the magnets 2I3 is actuated. Thismagnet corresponds to magnet I50 in the Wilcox patent and serves tostart the operation of the machine when the first selection signal isreceived and to continue such operation toplay as many records as havebeen selected. While the magnets 2I3 and 2 have been shown separatedfrom the phonograph mechanism in the drawings for sake of convenience,it is to be understood that they form a part thereof.

The invention has been described in one of its preferred forms, thedetails of which may be varied -by those skilled in the art withoutdeparting' from the scope thereof as defined by the'appended claims.

The invention claimed is:

1. In a receiver for a remote control system operated by modulatedcarrier signals received between said rectifier, said cathode, and saidconelectrodes,

trol electrode normally applying a biasing voltage to said controlelectrode to prevent current flow in said anode-cathode circuit,apparatus responsive to said carrier signals and associated withelectrode to change the potential thereof suiiiciently to permit currentflow in said anode-cathode circuit when a modulated signal is received,a relay connected to receive at least a part of the biasing voltage ofsaid control electrode and adapted to be actuated only when said biasingvoltage has been established at a predetermined amount, and a switch insaid anodecathodecircuit operated by actuation of said relay, saidswitch being open to prevent operation of said circuit when said relayis deenergized.

2. Ina receiver for a remote control system operated by modulatedcarrier signals received I on an alternating current power line, thesubcombination including a pair of electron valves each having acathode, an anode, a control electrode, and an anode-cathode circuit, arectifier receiving energy from said power line, and supplying directcurrent energy to both of said anode-cathode circuits, an electricaldevice to 'be controlled included in each of said circuits, a

grid biasing connection for each of said control connected to saidrectifier and normally applying a biasing voltage to said controlelectrodes to prevent current flow in said anodecathode circuits, a pairof tuned receiving circuits'each responsive to signals of a differentpredetermined carrier frequency and each associated with one of saidcontrol electrodes and adapted to change the potential thereofsufliciently to permit current flow in the corresponding anode-cathodecircuit when a signal of the predetermined carrier frequency isreceived, a relay associated with said grid biasing connections andreceiving at least a part of the biasing voltage and adapted to beactuated only when said biasing voltage has been established in a.predetermined amount, and

switching meanscontrolling both of said anode-cathode circuits operatedby said relay to prevent current

